This proposal requests a BIAcore 2000 Biomolecular Interaction Analysis (BIA) system for the East Tennessee State University College of Medicine. This system offers several advantages in studying macromolecular interactions: molecular interactions can be studied in real time, allowing measurement of association and dissociation rates as well as equilibrium binding constants. BIAcore detection can be used more extensively than fluorescent or absorption methods since it is sensitive to mass changes and requires no radio-labeling of reagents. Additionally, only one of the interacting molecules needs to be purified, so the technology can be study for studying impure mixtures. This instrument will greatly improve our ability to study molecular mechanisms controlling interactions of biomolecules in a broad range of systems: (1) Molecular aspects of the interaction of glucans with specific receptors and their affect on macrophage activation can be understood through binding analyses between carbohydrates and immune cells as well as by measurement of second messenger systems associated with macrophage activation. (2) The importance of peptide neurotransmitters can be established through identification of specific receptors in discrete brain areas and characterization of the interaction of closely related neuropeptides with their specific receptor subtypes. (3) Preconditioning of rabbit cardiomyocytes can be understood by using the BIAcore to characterize adenosine receptor subtypes; examination of adenosine receptor subtypes is currently limited by the availability adrenoceptors, and imidazoline receptors can be understood through more complex screening and by using kinetic analysis which is currently unavailable using other technologies.